The Evolution of Hearing in Conservatively Managed Acoustic Neuromas: In 70% of Patients, Hearing Loss is Progressive without Significant Risk Factors Identified for Preservation

Objective: To characterize the evolution of hearing in patients undergoing conservative management and presenting with hearing of 50 dB or better. To identify risk factors for hearing loss or preservation. Additionally, a comparison is made between “hearing preservation,” defined as “preservation within class,” and maintenance of PTA levels with respect to the contralateral ear.

Design: Retrospective cohort study.

Materials and Methods: Our database of patients with sporadic acoustic neuromas was searched to identify those presenting with a PTA of 50 dB or less and a minimal potential follow-up of at least 2 years. Audiological and demographic data were analyzed to characterize hearing evolution and risk factors. Hearing evolution was defined as change in PTA of the affected ear (0.5, 1, 2, and 3 kHz) over time relative to the contralateral ear. Statistical analysis employs SPSS with appropriate Chi-Square or t-tests.

Results: Of 196 patients identified, 132 had adequate data for analysis. Of the group as a whole, 30% preserved hearing at a rate equal to or better than that in the contralateral ear. This contrasts with 58% preserving hearing in the same “class” (defined in terms of PTA). The mean hearing loss in the group as a whole (hearing-losing patients only) was 4.1 dB (range, 0.12–25 dB). There were no significant risk factors for hearing preservation.

Conclusions: With long-term follow-up, approximately 30% of patients presenting with serviceable hearing can expect to preserve this hearing. This contrasts with a higher preservation rate if preservation within class outcome measure is employed.